Specimen Minimum Volume

Specimen Stability Information

Specimen Type

Temperature

Time

Urine

Frozen (preferred)

7 days

Refrigerated

24 hours

Reject Due To

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

NA

Reference Values

<3.00 millimoles/mole creatinine

Interpretation

Almost all patients with isobutyryl-CoA dehydrogenase deficiency
excrete an abnormal amount of iso-/butyrylcarnitine (C4) in their
urine. Some, but not all, affected individuals also excrete
elevated levels of isobutyrylglycine. Conversely, patients with
short-chain acyl-CoA dehydrogenase deficiency can have a normal
excretion of C4.

See Newborn Screening Follow-up for Isolated C4 Acylcarnitine
Elevations (also applies to any plasma C4 acylcarnitine elevation)
in Special Instructions for additional information.

Day(s) and Time(s) Performed

Monday, Wednesday, Friday; 8:00 a.m.

Analytic Time

2 days (not reported on Sunday)

Specimen Retention Time

2 months

Test Classification

This test was developed and its performance characteristics
determined by Mayo Clinic in a manner consistent with CLIA
requirements. This test has not been cleared or approved by the
U.S. Food and Drug Administration.